Varicella exposures from patients, visitors, and staff continue to occur in healthcare facilities. In a recent report from the National Surveillance System for Health Care Workers, 9 participating hospitals reported 72 varicella exposures from 1996 to 1999, involving 1,111 health-care workers. Depending on the patient and employee demographics for any particular healthcare institution, the number of these exposures can vary. Many healthcare facilities follow the guidelines of the Hospital Infection Control Practices Advisory Committee for non-immune employees exposed to varicella. These guidelines recommend that such employees be excluded from duty from 8 to 21 days after exposure to varicella. There is no standard definition of what constitutes exposure to varicella, which can result in employees' being excluded from duty on one or more occasions without having contracted chickenpox. We previously reported our experience of allowing non-immune employees exposed to varicella to work while wearing masks, checking daily for prodromal symptoms, and excluding these employees from duty only if such symptoms occurred. Since our original report from 1994, we have continued this practice without adverse consequences.